<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>动态生成下拉菜单</title>
</head>
<body>
    <select id="mySel">
        <option value="0">请选择</option>
    </select>
    <button id="genBtn">生成</button>


    <script>
        var arr = ["李红聪","小悦悦","秦海波","郑志康","郑帅","张薇","刁海建"];
        var genBtn = document.getElementById('genBtn');
        var mySel = document.getElementById('mySel');

        genBtn.onclick = function(){
            var optArr = ['<option value="0">请选择</option>'];
            var len = arr.length;

            for (var i=0;i<len;i++){
                optArr.push('<option>',arr[i],'<option>');
            }

            mySel.innerHTML = optArr.join('');
        };

    </script>
</body>
</html>